CVE-2021-30663
Published 2021-09-08 · Updated 2026-06-17 · Source product-security@apple.com
Summary
CVE-2021-30663 is a high-severity (CVSS 8.8) vulnerability in Apple Multiple Products. CISA added it to the Known Exploited Vulnerabilities catalog on November 3, 2021, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by November 17, 2021. CISA does not currently list it as used in ransomware campaigns. Apple has 96 vulnerabilities in the KEV catalog, 0 of them linked to ransomware.
All 96 known-exploited Apple vulnerabilities →Description
An integer overflow was addressed with improved input validation. This issue is fixed in iOS 14.5.1 and iPadOS 14.5.1, tvOS 14.6, iOS 12.5.3, Safari 14.1.1, macOS Big Sur 11.3.1. Processing maliciously crafted web content may lead to arbitrary code execution.
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CISA Known-Exploited Vulnerability
Product: Apple — Multiple Products
Name: Apple Multiple Products WebKit Integer Overflow Vulnerability
Date added: 2021-11-03 · Due: 2021-11-17
Required action: Apply updates per vendor instructions.
References
- https://support.apple.com/en-us/HT212335
- https://support.apple.com/en-us/HT212336
- https://support.apple.com/en-us/HT212341
- https://support.apple.com/en-us/HT212532
- https://support.apple.com/en-us/HT212534
- https://support.apple.com/en-us/HT212335
- https://support.apple.com/en-us/HT212336
- https://support.apple.com/en-us/HT212341